OBJECTIVES: 1. Amino acid sequencing and crystalographic studies of streptokinase will be continued. 2. Isolation and characterization of plasma and tissue plasminogen activator will be continued. 3. Structure, function and characterization of Factor V will be continued. 4. Physical and functional characterization of metabolic and coagulant contributors of platelets in non-anticoagulated platelet-rich plasma will be continued. 5. Structure (morphologic)-function correlation studies of platelets in the lysis of dilute platelet-rich plasma clots will be continued. 6. Structure-function studies of complement dependent endotoxin and collagen induced platelet aggregation, fusion and release will be continued with the objectives of initiating in vivo studies on animals. 7. Clinical studies of dilute clot lysis assay PF4 assays as a diagnostic tool for detection of deep vein thrombosis will be continued.